1. Field of the Invention
The present invention relates to a position control system in for example a numerical control system or industrial robot system, more particularly relates to a position control system capable of correcting positional deviation caused between a position of a controlled object and a target position with a high precision in accordance with a change of the relative positional relationship between mechanically related control axes.
2. Description of the Related Art
For example, in the position control of a numerical control machine tool, usually the position control of the cutting tool etc. is carried out by detecting the rotational position of the servo motor for driving a shaft for moving the cutting tool etc. by a rotation detector attached to the servo motor and controlling the rotation of the servo motor based on this detected value.
In such a numerical control machine tool, there are cases where even if the control of the rotation the servo motor is correctly carried out, correct position control of the cutting tool etc. cannot be carried out due to elastic deformation etc. caused in the mechanical elements constituting the machine tool.
There are methods for solving this problem, however, they are imprecise and complicated and involve other problems.